The effect of intralipid on pregnancy outcomes in women with previous implantation failure in in vitro fertilization/intracytoplasmic sperm injection cycles: A systematic review and meta-analysis

Interventions for recurrent embryo implantation failure: An umbrella review

BACKGROUND

Recurrent implantation failure (RIF) has a multifactorial etiology. An umbrella review was undertaken to evaluate the multiple proposed interventions.

OBJECTIVES

To summarize and assess the strength of evidence of interventions for RIF from published systematic reviews (SR) of randomized clinical trials (RCTs).

SEARCH STRATEGY

After prospective registration (PROSPERO CRD42023414255), a systematic search was conducted in the Cochrane Library, Scopus and Medline from inception until March 2024.

SELECTION CRITERIA

SRs of RCTs, with or without meta-analyses (MA), were included if they reported clinical pregnancy rates (CPR) or live birth rates (LBR).

DATA COLLECTION AND ANALYSIS

The methodological quality of the included SRs was appraised independently in duplicate using the AMSTAR 2 tool. For each intervention, the MAs of RCTs with statistically significant improvements were counted as a percentage of the total assessing the strength of evidence using the GRADE system.

MAIN RESULTS

A total of 47 SRs were included: 32 reviews covered immunomodulatory interventions, 10 (68 RCTs) covered uterine and endometrial interventions, one covered antibiotics, and four (69 RCTs) addressed mixed approaches, including laboratory interventions. AMSTAR 2 appraised 41 (88%) SRs as critically low or low, and 6 (12%) as moderate or high in quality. The SRs often had a level of overlap of RCTs (median 33.3%), inconsistent definitions of RIF, and varied comparisons for the interventions. Considering the significant meta-analytic evidence of high-moderate GRADE strength: Granulocyte colony-stimulating factor (G-CSF) showed improvement in CPR in 9/13 (69.2%) MAs and LBR in 1/7 (14%); intralipid infusion showed improvement in CPR in 4/6 (57.14%) MAs and LBR in 3/4 (75%); peripheral blood mononuclear cells (PBMC) showed improvement in CPR in 4/8 (50%) MAs and LBR 3/5 (60%); platelet-rich plasma (PRP) intervention showed improvement in CPR in 6/10 (60%) MAs and LBR in 1/5 (20%); human chorionic gonadotropins showed improvement in CPR in 3/3 (100%) MAs; growth hormone showed improvement in CPR in 1/1 (100%) MA; low molecular weight heparin showed improvement in CPR in 1/1 (100%) MAs and LBR in 1/2 (50%); hysteroscopy showed improvement in CPR in 1/2 (50%) MAs; and, intentional endometrial injury showed improvement in CPR in 3/4 (75%) MAs and LBR in 2/3 (66.66%).

CONCLUSIONS

Evidence syntheses of RCTs evaluating interventions for RIF suggest a consistent direction, with high to moderate strength, indicating that immunomodulatory treatments, including G-CSF, PBMC, PRP, intralipid infusion, and intentional endometrial injury are likely to be effective. However, this conclusion should be interpreted with caution due to the generally low methodological quality of the included studies and the clinical heterogeneity observed in most SRs.

Immune Cell Functionality during Decidualization and Potential Clinical Application

Due to a vast influx in the secretory phase of the menstrual cycle, leukocytes represent 40-50% of the decidua at the time of implantation. Their importance for the implantation, maintenance of pregnancy, and parturition are known yet not fully understood. Thus, in idiopathic infertility, decidual immune-related factors are speculated to be the cause. In this review, the immune cell functions in the decidua were summarized, and clinical diagnostics, as well as interventions, were discussed. There is a rising number of commercially available diagnostic tools. However, the intervention options are still limited and/or poorly studied. In order for us to make big steps towards the proper use of reproductive immunology findings, we need to understand the mechanisms and especially support translational research.

Immunomodulation for unexplained recurrent implantation failure: where are we now?

In brief

Immune dysfunction may contribute to or cause recurrent implantation failure. This article summarizes normal and pathologic immune responses at implantation and critically appraises currently used immunomodulatory therapies.

Abstract

Recurrent implantation failure (RIF) may be defined as the absence of pregnancy despite the transfer of ≥3 good-quality blastocysts and is unexplained in up to 50% of cases. There are currently no effective treatments for patients with unexplained RIF. Since the maternal immune system is intricately involved in mediating endometrial receptivity and embryo implantation, both insufficient and excessive endometrial inflammatory responses during the window of implantation are proposed to lead to implantation failure. Recent strategies to improve conception rates in RIF patients have focused on modulating maternal immune responses at implantation, through either promoting or suppressing inflammation. Unfortunately, there are no validated, readily available diagnostic tests to confirm immune-mediated RIF. As such, immune therapies are often started empirically without robust evidence as to their efficacy. Like other chronic diseases, patient selection for immunomodulatory therapy is crucial, and personalized medicine for RIF patients is emerging. As the literature on the subject is heterogenous and rapidly evolving, we aim to summarize the potential efficacy, mechanisms of actions and side effects of select therapies for the practicing clinician.

Effects of intralipid infusions on anti-trophoblast antibody (ATAb)-activities in patients with recurrent pregnancy loss: An observational report

PROBLEM

Some studies suggest intravenous intralipid infusions (IVIL) to be effective in the treatment of immune-mediated pregnancy failure. To this date it remains to be established, how IVIL might protect pregnancy and therefore a specific subgroup of RPL patients that might benefit from IVIL has not been defined. Anti-trophoblast antibodies (ATAb) have been associated with RPL and appear to mediate immune pathology. We have shown, that ATAb in vitro decrease HCG- and progesterone production pointing to a mechanism how ATAb interfere with normal pregnancies. We have measured ATAb-activities in patients undergoing off label IVIL-treatment.

METHOD OF STUDY

Ten RPL-patients with positive ATAb, determined by using the choriocarcinoma cellline JEG-3 and flow cytometry as described before, and otherwise unexplained RPL, received off-label IVIL during pregnancy. Two ATAb-positive RPL patients preferred expectant management. In addition, ATAb-activity was studied in pregnancies of two healthy ATAb-negative volunteers without miscarriages.

RESULTS

In RPL patients receiving IVIL, relative ATAb-activity decreased from an average of 56.8±17.0% to 20.8±11.0% (P < .001). The two RPL-patients without IVIL, aborted at 6+3gw and 7+4gw and embryonic genetic testing revealed euploid karyotypes. During pregnancies of the two healthy ATAb-negative individuals, ATAb-activities remained negative (16±9.8%) without significant changes (P = .22). Nine of the 10 pregnancies receiving IVIL proceeded uneventful with healthy newborns ≥37gw. One patient receiving IVIL aborted at 7+6gw and embryonic genetic-testing revealed a trisomy 16. No specific side effects concerning IVIL were noted.

CONCLUSIONS

Intralipid preparations during pregnancies of ATAb-positive RPL-patients significantly reduce ATAb-activities and this may indicate a therapeutic mechanism of IVIL.

The Impact of New Immunological Therapeutic Strategies on Recurrent Miscarriage and Recurrent Implantation Failure

Maternal-fetal immune dysregulation is one of the risk factors that increases the probability of embryo rejection and reproductive failure. The stimulation of immunological tolerance and suppression of immunological rejection are prerequisites for protecting embryos and preventing immunological attacks. Hence, it appears that immunomodulatory and immunosuppressive therapies can manage reproductive failures by controlling immune cells. The current medical literature has shown that immunotherapy approaches and cell therapy have promising results in improving pregnancy outcomes and live birth rates. These outcomes are obtained by regulating maternal immune responses, and exerting positive effects on human reproductive processes.

Unexplained recurrent implantation failures: Predictive factors of pregnancy and therapeutic management from a French multicentre study

INTRODUCTION

Recurrent implantation failure is defined as the absence of pregnancy after at least three transfers of good-quality embryos after in vitro fecundation/intracytoplasic sperm injection.

AIM

The aim of this study was to describe a multicentre cohort of women with unexplained RIF, to analyse the factors associated with clinical pregnancy and to evaluate the immunomodulatory therapies efficacy.

METHODS

Women were consecutively recruited from university departments with unexplained RIF.

RESULTS

Sixty-four women were enrolled with mean age 36 ± 3 years. The rates of clinical pregnancy in 64 women were compared in untreated and treated cycles and according to therapies used during the last prospectively followed embryo transfer. A clinical pregnancy after the transfer was noted in 56 % pregnancies on intralipids and in 50 % on prednisone, versus 5 % in untreated ones (p < 0.001). The 340 embryo transfers of these 64 women resulted in 68 clinical pregnancies and 18 live births. Clinical pregnancies were significantly more frequent in treated versus untreated embryo transfers (44 % vs 9 %; p < 0.001) with odds ratio at 8.13 (95 % CI 4.49-14.72, p < 0.0001). Cumulative pregnancy rates were higher for steroid-treated transfers than for untreated transfers when considering overall transfers before and after using steroids and also only those under steroids. Cumulative pregnancy rates were not different from steroid- and intralipid-treated embryo transfers CONCLUSIONS: In this multicentre study of women with unexplained RIF, use of immunomodulatory treatments before embryo transfer resulted in higher clinical pregnancy. Randomised, well-designed studies in well-defined population of RIF women are necessary to confirm our preliminary data.

The Fatty Acid Composition of Human Follicular Fluid Is Altered by a 6-Week Dietary Intervention That Includes Marine Omega-3 Fatty Acids

The fatty acid composition of human follicular fluid is important for oocyte development and for pregnancy following in vitro fertilization (IVF). This study investigated whether a dietary intervention that included an increase in marine omega-3 fatty acids, olive oil and vitamin D alters the fatty acid composition of human follicular fluid. The association of lifestyle factors with follicular fluid fatty acid composition was also investigated. Fifty-five couples awaiting IVF were randomized to receive the 6-week treatment intervention of olive oil for cooking, an olive oil-based spread, and a daily supplement drink enriched with vitamin D and the marine omega-3 fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) and 56 couples were randomized to receive placebo equivalents. Dietary questionnaires were completed, and samples of blood were taken before and after the intervention. Follicular fluid was collected at oocyte retrieval and the fatty acid profile assessed using gas chromatography. In the control group, individual fatty acids in red blood cells and follicular fluid were significantly correlated. Furthermore, a healthier diet was associated with a lower percentage of follicular fluid arachidonic acid. The follicular fluid of women in the treatment group contained significantly higher amounts of EPA and DHA compared to the control group, while the omega-6 fatty acids linoleic, γ-linolenic, dihomo-γ-linolenic, and arachidonic were lower. This is the first report of a dietary intervention altering the fatty acid composition of follicular fluid in humans. Further research is required to determine whether this intervention improves oocyte quality.